title: A role for a dioxygenase in auxin metabolism and reproductive development in rice.
abstract: Indole-3-acetic acid (IAA), the natural auxin in plants, regulates many aspects of plant growth and development. Extensive analyses have elucidated the components of auxin biosynthesis, transport, and signaling, but the physiological roles and molecular mechanisms of auxin degradation remain elusive. Here, we demonstrate that the dioxygenase for auxin oxidation (DAO) gene, encoding a putative 2-oxoglutarate-dependent-Fe (II) dioxygenase, is essential for anther dehiscence, pollen fertility, and seed initiation in rice. Rice mutant lines lacking a functional DAO display increased levels of free IAA in anthers and ovaries. Furthermore, exogenous application of IAA or overexpression of the auxin biosynthesis gene OsYUCCA1 phenocopies the dao mutants. We show that recombinant DAO converts the active IAA into biologically inactive 2-oxoindole-3-acetic acid (OxIAA) in vitro. Collectively, these data support a key role of DAO in auxin catabolism and maintenance of auxin homeostasis central to plant reproductive development.
authors.affiliation: National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhao
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xi
authors.initials: X
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Shichang
authors.initials: S
authors.lastname: Liu
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Yu
authors.forename: Yulong
authors.initials: Y
authors.lastname: Ren
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Zheng
authors.forename: Kunneng
authors.initials: K
authors.lastname: Zhou
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang
authors.forename: Xiuping
authors.initials: X
authors.lastname: Guo
authors.forename: Ying
authors.initials: Y
authors.lastname: Gai
authors.forename: Chuanyin
authors.initials: C
authors.lastname: Wu
authors.forename: Huqu
authors.initials: H
authors.lastname: Zhai
authors.forename: Haiyang
authors.initials: H
authors.lastname: Wang
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wan
mesh_terms: D049308:Dioxygenases / Q000235:genetics / Q000378:metabolism*; D006706:Homeostasis; D007210:Indoleacetic Acids / Q000378:metabolism*; D009154:Mutation; D012275:Oryza / Q000201:enzymology* / Q000502:physiology; D051479:Plant Infertility / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011058:Pollen / Q000502:physiology; D054817:Pollination / Q000235:genetics
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; C030737:indoleacetic acid; D049308:Dioxygenases